Cantilever sensors have enjoyed considerable interest among researchers because of their high sensitivity and their potential for high throughput applications with label-free reagents. Resonant-mode cantilever sensors respond to attached analytes by reduction in resonant frequency. The change in resonant frequency is proportional to analyte concentration, and can be measured by a variety of methods, which can include integrated transducing elements within the oscillating cantilever and external instrumentation that measures the cantilever oscillation amplitude. In both cases, the actuation of the cantilever can be provided by natural thermal fluctuations or by actuating the base of the cantilever electromechanically.
There have been several attempted innovative methods for measuring resonance, both internal and external to the sensor. However, more sensitive sensors continue to be sought.